A Review of Recent Requirements for Inverter-Based Resources and Grid-Forming Technologies

Inverter-based resources (IBRs) are playing a major role in modern power systems, and the installation of IBRs is still growing in recent years, which necessitates the continuous development of grid codes and requirements, e.g. National Grid GC0137 in 2021 and IEEE Std. 2800 in 2022. In the meanwhile, conventional control strategies (i.e., grid-following, GFL) are facing challenges when dealing with a high-percentation-IBR power system, especially in faulty conditions. Considering this, new control schemes like grid-forming (GFM) control has been put forward to offer a stable voltage for the grid. However, certain concepts and definitions remain unclear. With the above concerns, a review of the recent requirements for IBRs and GFM technologies is given in this paper, where further perspectives and open discussions are presented.